Pakistan's military said it killed 76 militants in two separate air strikes on Tuesday as part of a major offensive against the Taliban and other insurgents in a tribal region near the Afghan border.

The first air strike took place near Datta Khel area of North Waziristan tribal district while the second strike was focused on Datta Khel.

At least 35 militants were killed in air strikes on Sunday in the same area.

"In precise aerial strikes, 53 terrorists including some foreigners were killed," the military said in a statement, adding later that another 23 were killed in further strikes.

Pakistani officials refer to the Arab and Central Asian militants who fled to the tribal lands after the US-led invasion of Afghanistan in 2001 as "foreigners".

"Six terrorist hideouts, an ammunition dump and seven explosive-laden vehicles were also destroyed" in the air strikes, the statement added.

The conflict zone is off-limits to journalists, so there is no way to independently verify the number and identity of those killed.

Pakistan began a long-awaited push to clear insurgent bases from North Waziristan last June after a bloody Taliban attack on Karachi airport finally sank faltering peace talks.

Air strikes, artillery, mortars and ground troops have all been used to take back territory.

The army has intensified its offensive since the Taliban's massacre of 150 people, 134 of them children, in a school in the northwestern city of Peshawar in December.

The semi-autonomous tribal areas on the Afghan border have for years been a hideout for Islamist militants of all stripes, including Al-Qaeda and the Pakistani Taliban as well as foreign fighters such as Uzbeks and Uighurs.